METHOD FOR MONITORING A COOLANT CIRCUIT OF AN INTERNAL COMBUSTION ENGINE

摘要

The invention relates to a method for monitoring a coolant circuit (16) of an internal combustion engine (10), according to which an electronic control unit (42) compares a measured actual value of a temperature of the internal combustion engine (10) with a set value of the temperature that has been determined from a saved model, said model being based on the energy throughput of the internal combustion engine (10) and the control unit (42) sets a first error signal, if the deviation of the actual value of the temperature from the set value of the temperature exceeds a predetermined quantity. According to the invention, a second error signal is set that indicates a possible lack of anti-freeze, if: a starting temperature lies below the freezing point of water; a first error signal existed; the first error signal no longer exists after a predetermined time period that represents a function of the temperature when the internal combustion engine (10) is started; and an energy balance of energy produced exceeds a threshold that represents a function of the temperature when the internal combustion engine (10) is started.